Fine structure of conidiogenesis in the mosquito pathogen Culicinomyces clavosporus (Deuteromycotina)
Conidiogenesis in Culicinomyces clavosporus Couch, Romney, and Rao (Deuteromycotina) is initiated with the growth of conidiogenous cells from vegetative hyphae. Formation of the primary conidium itself begins with a conidial initial which grows through the bilaminar wall at the tip of the conidiogenous cell, wall remnants of the conidiogenous cell often collapsing to form a collarette at the base of conidia. This factor, in addition to the fixed conidiogenous locus, shows that the conidiogenous cell is a phialide. As the conidial initial enlarges, a bilaminar well is synthesized around the cell, and cytoplasmic organelles migrate through the neck of the phialide into the initial. Once the conidium is mature, a septum is formed across the open neck of the phialide and two organelles (dense-core vesicles and autophagosomes), unique to conidia, become evident. The mode of development is enteroblastic–phialidic; Culicinomyces clavosporus is placed therefore in section IVB of the Hughes–Tubaki–Barron classification scheme described by B. Kendrick for the Deuteromycotina.